This application is based upon and claims the benefit of priority from the prior Japanese Patent Applications No. 2000-397311, filed Dec. 27, 2000, No. 2001-002163, filed Jan. 10, 2001; No. 2001-005007, filed Jan. 12, 2001; No. 2001-016217, filed Jan. 24, 2001; and No. 2001-218569, filed Jul. 18, 2001, the entire contents of all of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to a small antenna and a manufacturing method thereof used for small telecommunication equipment such as cellular phones.
2. Description of the Background Art
In a small antenna, the miniaturization is requested as much as possible to reduce the mounting area to a circuit board, etc. A small antenna is mounted in small telecommunication equipments such as cellular phones. Therefore, it is requested to a small antenna that thickness thereof is as thin as possible in addition to the miniaturization.
It is considered that the following molding methods, so-called the insert molding method is employed to this kind of the small antenna. That is, the antenna element is integrated with the resin molded body by setting the antenna element formed to the necessary shape in the mold and injecting the resin.
In a small antenna as mentioned above, the strength of the small antenna lowers, when the area of the antenna element is reduced as much as possible or the thickness of the resin molded body is thinned as much as possible to miniaturize the antenna. Therefore, the antenna becomes easily deformed when producing. The deformation of the antenna influences the impedance characteristic of the antenna. Therefore, it is important to prevent the deformation when the antenna is produced.
An object of the present invention is to provide a small antenna and a manufacturing method thereof, in which the crack of the resin molded body and the deformation of the antenna element are hardly generated.
The small antenna according to the first aspect of the present invention is characterized by comprising: a planar antenna element; and a resin molded body integrally molded with the antenna element, in which the resin molded body has a thin part and a thick part on both sides of the antenna element, and a gate portion at a resin molding is provided to the thin part.
The small antenna according to the second aspect of the present invention is characterized by comprising: a planar antenna element; a resin molded body integrally molded with the antenna element; and a hole formed to the antenna element.
The small antenna according to the third aspect of the present invention is characterized by comprising: an antenna element; and a resin molded body in which the antenna element is embedded or which is accumulated, the antenna element having a terminal extended to an outside of the resin molded body, in which the terminal comprises a narrowed portion with narrow width of a conductor at a base thereof, and the narrowed portion is bent at an outside of the resin molded body.
The manufacturing method of the small antenna according to the fourth aspect of the present invention is characterized by comprising: setting an antenna element to place the antenna element between a first mold and a second mold of the mold; and integrally molding a resin molded body to embed the antenna element by injecting the resin to the mold, in which a depth of a cavity of the first mold is shallower than a depth of a cavity of the second the mold, and a gate portion is provided to the first mold.
The manufacturing method of the small antenna according to the fifth aspect of the present invention is characterized by comprising: setting an antenna element in a mold; performing injection molding by injecting a resin which is a dielectric material in the mold; and ejecting a resin molded body by striking an ejector pin to the resin molded body, when the mold is opened and the resin molded body after the injection molding is taken out, in which the resin molded body has the surfaces whose thickness are different at both sides of the antenna element, and ejecting including striking the ejector pin to a thicker surface of the resin molded body and ejecting the resin molded body.
The manufacturing method of the small antenna according to the sixth aspect of the present invention is characterized by comprising: setting an antenna element in a mold; performing injection molding by injecting a resin which is dielectric material in the mold; and ejecting a resin molded body by striking an ejector pin to the resin molded body, when the mold is opened and the resin molded body after the injection molding is taken out, in which ejecting includes striking the ejector pin to a position where a part to which the resin molded body is picked up is avoided and ejecting the resin molded body.
The manufacturing method of the small antenna according to the seventh aspect of the present invention is characterized by comprising: setting an antenna element by placing at least a part between parting faces of a mold; and injecting a resin in the mold, in which setting includes setting the antenna element to form a space in a part where the antenna element is not placed in the parting faces.
The manufacturing method of the small antenna according to the eighth aspect of the present invention is characterized by comprising: setting an antenna element by placing at least a part between parting faces of the mold; and injecting a resin in the mold and performing a molding, in which a plurality of support parts extended to an outside to at least two opposite sides in the antenna element are integrally formed, and setting includes setting the antenna element to place the support parts between the parting faces of the mold in the parting faces, and form a space in a part where the support parts between the parting faces of the mold is not placed.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.